Well Casing Perforator Tool

ABSTRACT

A perforator tool that offers a simple solution to create multiple perforations at different lengths and locations inside a well casing. The perforator tool includes a tool housing that holds all of the components together along with providing a means of connecting the perforator tool to the drill pipe, and a means of transferring pressurized fluid from the drill pipe to use to engage the knife into the well casing, a knife that is used to create the perforation puncture(s) inside the well casing, a pin to hold and allow the knife to pivot inside the tool housing, and a spring connected to a set screw to be able to adjust the spring force to disengage the knife from the well casing.

CROSS REFERENCE TO RELATED APPLICATIONS

U.S. Pat. No. 1,500,829

U.S. Pat. No. 1,910,851

U.S. Pat. No. 1,063,277

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable to this application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention, in general, pertains to tools for perforating water well casings and more particularly to perforating smaller diameter water well casings without removal of the tool to complete multiple wall piercings throughout the entire water well casing length.

2. Description of the Related Art

Water well casing perforators are well known in the art. U.S. Pat. No 1,063,277 discloses a perforator, in which, the knife is engaged through the use of a drill string. U.S. Pat. Nos. 726,625; 1,500,829; and 1,910,851 disclose of a star wheel perforator that require the removal of the drill string and perforator tool before the development of the well can be carried out. U.S. Pat. No 4,182,418 discloses a tool for a star wheel perforator that engages the star wheel via pneumatic cylinder within the tool that does not require the removal of the tool before the development of the well.

OBJECTS AND ADVANTAGES OF THE INVENTION

What is needed is a water well casing perforator which is suitable for small, medium, and large diameter water well casings. In particular, a simple, easy to use, inexpensive to manufacture or purchase, and durable water well casing perforator for small diameter casings, in which, based off the prior art knife and star engagement method, is not possible to use on small diameter casings due to their complexity and internal components that make up each of the prior arts. It is therefore a principal object of this invention to produce a tool which is capable of perforating large diameter, but in particular, small diameter, 6 inches or less, water well casings without the use of a drill string or pneumatic cylinder to engage the knife.

It is a further object of this invention to produce a single tool by which perforation is carried out through the use of water pressure from the water rotary drilling machine.

It is a further object of this invention to produce a single tool by which perforation hole size can be either intermediate or continuous throughout the well casing.

Other objects and advantages will be apparent to those skilled in the art with reference to the accompanying drawings and specifications.

Operation

It is well known that drilling in formations comprised of sand and gravel requires the well to be perforated after the well casing is installed instead of prior to the installation of the well casing. Perforation beforehand is not possible. It is also known that further perforation of water wells to increase available flow output from them requires that the well be perforated after installation if perforation was not completed or correctly completed beforehand. It is also well known that perforation must be completed to decommission all water wells, regardless of size.

With the present invention, the drill operator will be able to connect the pipe perforator to the end of the drill rod and insert the pipe perforator into the well casing via the drill rod. Once the operator is at the perforation depth inside the well casing, they will engage the drill rigs water supply at the specified water pressure. The pressurized water will travel down the drill pipe, through the housing of the perforator, and start to engage the cutting knife into the side wall of the water well casing. Simultaneously, as the operator supplies the perforator with pressurized water, the operator will engage the drill rig to pull vertically up on the drill rod to help engage the knife and create the puncture in the side of the well casing. Once engaged, the operator will disengage the pressurized fluid and the knife is held in place inside the well casing wall. The total length the operator pulls up on the perforator will determine the total length of the puncture in the side wall of the well casing. In theory, the operator could create a puncture the entire length of the well casing. Once the desired puncture is created, the operator will lower the perforator, via the drill pipe, so the spring, inside the perforator housing, will push the knife back into the housing. From there the operator can move to the new perforation location inside the well casing.

A pipe perforator, according to the present invention, does not require the drill string, nor a pneumatic cylinder, or any other complex features to engage the knife into the side of a well casing in order to perforate it. In addition, it has numerous advantages over these previous designs. Firstly, it is low cost to manufacture as it does not require the complex features of the previous inventions. Secondly, it can be adaptable to any size well casing as the housing only needs to be the same size, or less, diameter as the well casing itself. The previous art is limited in size based off the drill string and the cylinder sizes used to engage the knife. Finally, the perforator tool is extremely easy to use, along with having minimal parts to fail during operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features, and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

FIG. 1 Overview of the perforator tool and its components.

FIG. 2 Top view of the perforator tool assembly.

FIG. 3 Cross-sectional view of the perforator tool taken along section A-A of FIG. 2, particularly showing the pipe perforator when it is in its disengaged state outside the well casing.

FIG. 4 Cross-sectional view of the perforator tool taken along section A-A of FIG. 2, particularly showing the perforator tool when it is in its engaged state outside the well casing.

FIG. 5 Top view of the perforator tool inserted inside the well casing.

FIG. 6 Cross-sectional view of the perforator tool inside the well casing taken along section B-B of FIG. 5, particularly showing the perforator tool when it is in its disengaged state inside the well casing.

FIG. 7 Cross-sectional view of the perforator tool inside the well casing taken along section B-B of FIG. 5, particularly showing the perforator tool creating the perforation puncture when it is in its engaged state inside the well casing.

DETAILED DESCRIPTION OF THE INVENTION A. Overview

Turning now descriptively to the drawings, in which similar reference characters denote similar elements through the several figures. FIGS. 1 through 7 illustrate a pipe perforator tool 1 that is connected to the end of a drill pipe 9 that is to be inserted down into a well casing 8 inside the ground 9 where the well casing 8 must be perforated at varying depths, varying locations, and varying perforation puncture 8.1 sizes are to be created inside the well casing 8.

B. Perforator Tool

The perforator tool 1 is comprised of a knife 3, a pin 4, a spring 5, a set screw 6, and a tool housing 2, in which, the tool housing 2 is comprised of a knife chamber 2.1, a fluid channel 2.2, a threaded rod connection 2.3, and a threaded spring enclosure 2.4 to contain all of the perforator tool 1 components together as shown in FIGS. 1, 3, and 4.

The diameter of the tool housing 2 can vary depending on the well casing 8 diameter. Typically, for smaller well casing 8 sizes, 6-inches or less in diameter, the tool housing 2 diameter is equal to, or slightly less than, the drill pipe 9 diameter as shown in FIG. 6.

The tool housing 2 knife chamber 2.1 is large enough to house the knife 3 such that, when disengaged, the perforator tool 1 can travel vertically inside the well casing 8 via the drill pipe 9 shown in FIG. 6.

The tool housing 2 fluid channel 2.2 is machined to allow fluid 10 to flow from the inside of the drill pipe 9, through the threaded rod connection 2.3, into the fluid channel 2.2 and into the knife chamber 2.1 to exert an outward force on the top of the knife 3 as shown in FIG. 7.

The tool housing 2 threaded rod connection 2.3 threads can be machined to thread onto any size drill pipe 9.

The tool housing 2 threaded spring enclosure 2.4 is machined to allow the spring 5, that is attached to the set screw 6, to be horizontally adjustable to increase or decrease the spring 5 force against the knife 3 inside the tool housing 2 to allow for the knife 3 to be disengaged back into the knife chamber 2.1 as shown in FIGS. 3 and 4.

C. In Use

In use, the perforator tool 1 is used to create perforation puncture(s) 8.1 inside the well casing 8 at varying depths. The perforator tool 1 is capable of creating perforation puncture(s) 8.1 at multiple sizes, at a single location, or in multiple locations inside the well casing 8. To do so, the perforator tool 1 is threaded onto the end of the drill pipe 9, and the drill operator lowers the drill pipe 9 into the well casing 8 as shown in FIG. 6. Once the perforator tool 1 is at the desired depth inside the well casing 8, the drill operator simultaneously engages the drill rigs pressurized fluid 10 and pulls vertically upward on the drill pipe 9. The fluid 10 travels down the inside of the drill pipe 9, through the threaded rod connection 2.3, into the fluid channel 2.2, and the fluid 10 exerts an outward force onto the knife 3 causing the knife 3 to engage the well casing 8 wall to create a perforation puncture 8.1 into the side of the well casing 8 as shown in FIG. 7. Once engaged, the operator disengages the fluid 10. The drill operator pulls vertically upward on the drill pipe 9 to the desired perforation puncture 8.1 length on the inside of the well casing 8. Once the desired perforation puncture 8.1 is complete, the operator pushes the drill pipe 9 vertically downward inside the well casing 8. The spring 5 force pivots the knife 3 around the pin 4 inside the tool housing to disengage the knife 3 and locate it back into the knife chamber 2.1 as shown in FIGS. 6 and 7. The operator now moves the perforator tool 1 to the next desired location to complete more perforation punctures 8.1 inside the well casing 8 as outlined above. Once all perforation punctures 8.1 are completed, the drill operator removes the drill pipe 9 from the well casing 8 and unthreads the perforator tool 1 from the drill pipe 9.

What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations for the invention's possible circuitry on a perforator tool 1. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect. 

1. A perforator tool 1 mounted to a drill pipe 9 and is used to create perforation puncture(s) 8.1 inside a well casing 8, comprising: A tool housing 2, in which said tool housing 2 internally contains a knife chamber 2.1, a fluid channel 2.2, a threaded rod connection 2.3, and a threaded spring enclosure 2.4, a knife 3 for creating said perforation punctures 8.1 into said well casing 8, a pin 4 to hold said knife 3 inside said knife chamber 2.1, a spring 5 to disengage said knife 3 into said knife chamber 2.1 around said pin 4, and a set screw 6 to adjust said spring 5 force inside said threaded spring enclosure 2.4.
 2. A method for perforating a well casing 8 with a perforator tool 1 comprising: Threading on said perforating tool 1 onto a drill pipe 9 and lowering said perforator tool 1 into said well casing 8, via said drill pipe 9, to a perforator puncture 8.1 location inside said well casing 8, engaging a knife 3 housed inside said perforator tool 1 into said well casing 8 by a fluid 10 that is supplied by said drill pipe 9 and a series of housings 2, 2.1, 2.2, and 2.3 inside said perforator tool 1, where a spring 5 along with a set screw 6 and a pin 4 located internally to said perforator tool housing 2 disengages said knife 3 from said well casing 8 to be able to complete multiple said perforator punctures 8.1 into said well casing
 8. 